The codes and standards affecting PV equipment and system installations are almost as varied as the equipment itself. The Canadian Standards Association (CSA), California Energy Commission (CEC), Institute of Electrical and Electronics Engineers (IEEE), International Code Council (ICC), International Electrotechnical Commission (IEC), National Fire Protection Association (NFPA), Underwriters Laboratories (UL) and countless other agencies all have their own opinion as to how PV system components should be manufactured and how PV systems should be installed. As a result, there is no unanimity regarding what equipment is considered safe for use and what constitutes proper installation.

While the manufacturer’s installation instructions generally take precedence over other requirements, many local or state jurisdictions have additional requirements beyond those found in the National Electrical Code. Furthermore, when a PV system is utility owned and operated, the installation is technically outside the scope of the NEC. But what exactly is a utility? This is a very important distinction because the NEC generally requires the use of equipment listed to UL standards. However, if a PV installation is not subject to the NEC, the use of equipment designed to meet other standards, such as those established by the IEC, may be permitted.

Since the standards to which PV equipment must conform vary by context, as do the applicable codes, it is incumbent on designers and installers to understand the regulatory context within which they are working. This regulatory context influences what equipment and installation practices are likely to be acceptable to the AHJ and the interconnected utility. Because there is no universal set of requirements, system designers and installers must be proactive about communicating with AHJs and utilities to streamline project permitting, inspection and commissioning.

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